For all its promise, embryonic stem cell research has been slow going in the last few decades. Ethical quandaries and scientific difficulty have conspired to keep the next big advance just out of reach, but a new study published this week in the journal Cell could kick off a new age of interest in stem cell therapies. Researchers from Oregon Health & Science University have managed to clone human embryonic stem cells using unfertilized eggs and human skin cells.

The process is very similar to the method used over a decade ago to clone Dolly the sheep, but the aim here was not to produce a human clone. Rather, scientists wanted to make a line of stem cells that would not be rejected by a recipient’s own immune system, In fact, according to Professor Shoukhrat Mitalipov from Oregon Health & Science University, it is unlikely the embryos used in the study had any hope of developing into viable human clones.

To create these new stem cell lines, researchers removed the DNA from donated unfertilized human eggs. A skin cell from a different individual was then inserted into the egg cell. The trick that made this advance possible is in finding a way to entice that cell to begin dividing. Mitalipov and his team eventually found that exposure to precisely-timed electric pulses and a chemical bath with a bit of caffeine did the trick.

The result is a small bundle of embryonic stem cells that match the genotype of the skin cell donor, not the egg donor. Stem cells created in this process are known as pluripotent, because they can differentiate to become a wide variety of cell types. They could conceivably be turned into cardiac muscle, nerve cells, pancreatic cells, or any number of other tissues to treat disease.

Additionally, the maturation process is well established for the cells in this study. They actually appear to become functional adult cells when harvested. Researchers even managed to create cardiac cells that contract just like the real thing. Previous stem cell discoveries using only regressed skin cells come with many unanswered questions, thus the continued use of human embryos.

Having a way to manufacture stem cells that match a person’s DNA is revolutionary in stem cell therapy. If you implant cells that don’t match someone’s genotype, they are likely to be rejected. This is why transplant patients must take immunosuppressive drugs. This process could lead to treatments where doctors create new tissues to treat patients that are essentially their own cells.

Other researchers are anxious to attempt the process themselves, and hopefully confirm Mitalipov’s results. The entire paper is online if you want to check it out.